In the prior art, after receiving a packet, a forwarding element needs to determine a data format of the packet, for example, the forwarding element determines whether the packet is an Internet Protocol (IP) packet or a Multiprotocol Label Switching (MPLS) packet, to process the packet. For example, after receiving an Ethernet packet, a switch needs to determine, according to a port table, that a protocol with which the Ethernet packet complies is the Media Access Control (MAC) Protocol. Then, the switch parses a MAC Protocol header of the Ethernet packet according to the MAC Protocol, to acquire a destination MAC Protocol address of the Ethernet packet.